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Short Period Variables: DY HER vs. DL HER for My Winter CCD Program?

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Short Period Variables: DY HER vs. DL HER for My Winter CCD Program?

Hello! Last winter, I observed DL HER. It is a RRAB/B star with a period of about 14.2 hours. I am going to observe it this winter as well.

    DY HER comes up about an hour earlier, and I have started to observe it till I am able to image DL HER. DY HER is a DSCT star with a period of about 3.6 hours. I can continue to put in 30 to 60 minutes to observe it before switching to DL HER this winter, but that would be bare minimum coverage given its period.

    I suspect that I should probably concentrate on one or the other this winter during nights when I image SPVs. Both are on SPP list.

    Are they equally important for data, or might one be more desirable if I select only one? Best regards.


arx's picture
DY Her is personally favoured

Hello Mike,

My personal opinion would be to favour the delta Scuti star DY Her. The literature I have tried to dip into briefly suggests that it may be a component of a binary system, but the reference suggesting that shows scattered data in an O-C diagram which it seems to me would be difficult to analyse precisely.

There are many time series observations in the AID on this star, which would be interesting to study, and I'm sure adding to them with time series sufficiently precise to allow accurate determination of times of maximum would be valuable.


Roy Axelsen

Brisbane, Australia


Thank you!


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